Pneumatically operated tool

ABSTRACT

A pneumatic clip tool for clinching clips about wires. The tool is configurated to minimize the likelihood of jamming and is designed to speed the clearing of jams. A fixed position clinching jaw below the driver is quickly moved out of position to provide access to the driver assembly from below. The jaws are L-shaped to butt on closing and have steps and serrations at their line of juncture, thereby to minimize jamming of a clip in the jaw and driver assembly when the tool is in use. A supplemental retracting force is selectively provided when the usual retracting piston and cylinder is ineffective to return the driving piston to an inactive position to ready it for a new cycle of operation. The magazine and follower are proportioned so that the last few clips are not fed, to minimize tumbling and jams which occur for that reason. The tool also includes an antibackup assembly to prevent the rearward movement of clips fed to the driver, thereby eliminating the possibility of tumbling for that reason.

nited States Patent 1191 Plunkett Dec. 3, 1974 PNEUMATICALLY OPERATED TOOL [75] Inventor: Larry D. Plunkett, Crystal Lake, 111. Primary Examl' wr Al Lawrence Sm'th Assistant Exam1ner-K. .1. Ramsey 1 Assigneer Sigmde P fi Glenview, Ill. Attorney, Agent, or FirmDressler, Goldsmith, 22 Filed: Dec. 27, 1972 Clement & Gordon [21] Appl. No.: 318,822 [57] ABSTRACT A pneumatic clip tool for clinching clips about wires. [52] US. Cl 29/243.56, 248/52, 285/61, The tool is configurated to minimize the likelihood of 29/212 D, 29/203 D, 140/93 D jamming and is designed to speed the clearing ofjams. [51] Int. Cl B23p 11/00, B2lf /06 A fixed position clinching jaw below the driver is [58] Field of Search 29/203 H, 203 D, 208 D, quickly moved out of position to provide access to the 29/211 D, 212 D, 243.56, 243.57; 53/138 R, driver assembly from below. The jaws are L-shaped to 138 A; 91/152; 72/410, 399; 144/32; 248/17, butt on closing and have steps and serrations at their 51, 52; 285/61; 138/107 line of juncture, thereby to minimize jamming of a clip in the jaw and driver assembly when the tool is in use. [56] References Cited A supplemental retracting force is selectively provided UNITED STATES PATENTS when the usual retracting piston and cylinder is inef- 593,064 11/1897 Albree 248/17 ffictive to realm the driving i to fi g i posi 838,008 12/1906 Chandler et al. 29/243.56 "9 to ready for a new CYC e 9 Operatlon' e 1,575,476 3/1926 Cook 91 152 x time and follower are Proportwned 80 that the last 2,183,978 12/1939 Sorenson 29/243.56 x w clips are not fed, to minimize tumbling and jams 2,574,81 1 1 1/1951 Blumensaadt... 29/212 D UX which occur for that reason. The tool also includes an 2,831,302 4/1958 Jensen et a1. 53/138 A antibackup assembly to prevent the rearward move- 2'969545 H1961 Allen.

29/212 D ment of clips fed to the driver, thereby eliminating the 3,368,322 2/1968 Yasui 53/138 A possibility of tumbling for that reason 3,529,342 9/1970 Burgess et al 29/212 D 3,666,220 5/1972 Rider 248/52 11 Claims, 11 Drawing Figures Y 3 75 5'25, 0 4 3 62-144 g2 L 1 4.2 5 i In 32 mu 254$ 110. 13 52 T D 2 J35 7 39 6 123 732 524; 1 3, 94 v 2 1' f 1" j. I: 47 42 36 a7 9 124 ,i: i 38 44 e 9 a l i L 5 2 6 o -f I 5' i?" -E f 3/ 7O 53 3 l 2 74$ 740 PATENTELBEC 31w SHEET m 3 aasmn LEE; :5

mm mm W mm PNEUMATICALLY OPERATED TOOL BACKGROUND OF THE INVENTION 1. Field of Invention This invention relates to an improved clip tool and more particularly to an improved pneumatically operated clip tool having a pair of clinching jaws adapted to clinch a clip about two or more wires. The clip tool is designed to be used as with generally U-shaped metal clips adapted to be fed from a magazine associated with the clip tool. a

2. Description of the Prior Art There is a wide variety of clip tools known to the art and many of these are described in issued patents. A principal disadvantage of many known clip tools is that they too frequently malfunction during operation and for various reasons which are not always attributable to the tools themselves. Because clip tools are most often used in assembly lines, when they malfunction, either the tool must be replaced or the entire assembly line must be shut down while the malfunction is corrected.

One of the most common malfunctions of clip tools is jamming, i.e., the jamming ofa clip with the tool, requiring the tool to be disassembled or otherwise worked with to clear the jam. Jams result from tolerance build ups in the tool, from tumbling of clips as they are fed to the driver, from imperfect clips and the like.

SUMMARY OF THE INVENTION In accordance with the present invention, a clip tool is provided in which the occurrence of jamming malfunctions is minimized and in which jams which do occur are much more easily cleared than with presently available tools. A tool in accordance with this invention is preferably of the pneumatically operated type and comprises a casing, a reciprocable clip driver mounted in the casing and means for reciprocating the driver. The reciprocating means comprises a cylinder in the casing and a piston operatively connected with the driver for moving the driver to an inactive position and to a second clinching position. The tool further provides a clinching anvil disposed beneath the driver means which is adapted to cooperate with the driver to clinch a clip, as about a pair of elongate wires.

The clinching anvil of the improved clip tool of this invention comprises a pair of generally L-shaped clinching jaw members, one of which is fixedly positioned, and the other of which is movable, preferably with the driver means. to a juxtaposed position with the fixedly positioned jaw member to form a closed bottom anvil section into which the driver means drives a clip to clinch it about two or more-wire means to be secured to each other. j

The fixedly positioned jaw member is preferably readily released, as by a pull pin, from its fixed position, toswing away, thereby to provide free and open access to the driver from below the driver means. By so mounting the fixedly positioned jaw member, in the event that a jam should occur in the tool, access is readily and quickly provided to the area where the jam has occurred, thereby to permit clearing the jam rapidly and easily. v

' The clinching jaw members are specially configured to minimize the possibility of jams thereat during a clinching operation. To that end, the confronting edges of the Lshaped jaw members are correspondingly serrated and mesh as they move into engagement to form the closed bottom anvil section. As such, it is not possible for legs of a clip to wedge themselves between the confronting faces of the jaw to jam the tool. Furthermore, the driver means and movable jaw member define cooperating tongue and groove means in their confronting surfaces. This then prevents the entry of portions of a clip being driven from moving upwardly between those surfaces which sometimes results in the jamming of a clip tool. Moreover, the tongues protrude slightly from the driver means to aid the clinching of the clip by directing the leading portion of the legs inwardly around the wires. Additionally, the L-shaped jaw members each define upwardly facing step'means positioned adjacent the juncture of the members when they are in their closed bottom anvil position. These upwardly facing steps allow the portions of the clip legs to cross the juncture as a clip is being driven and clinched without striking the edge of the jaw, further minimizing the possibility of tool jamming during clinching operations.

Another source of possible tool jamming is eliminated in accordance with this invention, i.e., by preventing tumbling of clips as they are fed in the tool beneath the driver. In accordance with this invention a magazine is secured to the casing, the magazine being positioned with a clip discharge end adjacent a feed opening in the casing. A magazine follower is provided to feed clips which may be interconnected in ribbon fashion leg to leg across their side edges into the feed opening to be driven by the driver means. An antibackup assembly for preventing movement of the clips fed for driving is provided and comprises a link for engaging a clip leg to prevent the backward movement of clips. The link is resiliently biased to a retracted position as clips are moved through the feed opening and then resiliently returns to its active position to act against a leg of a clip to prevent the clips backward movement. That minimizes the possibility of clips tumbling in the area inthe tool beneath the driver blade and in the feed opening, thereby minimizing the possibility of jamming resulting from clip tumbling. Furthermore, the magazine preferably incorporates a follower which is proportioned with the magazine so that the follower cannot feed all of the clips in the magazine through the feed opening. As such, several clips always remain in the magazine to serve to back up the clip fed through the feed opening beneath the driver means to assist in orienting it and preventing its tumbling. That also assists in minimizing the possibility of tool malfunction resulting from clip tumbling and jamming.

In the event that a jam should occur during the driving stroke of a tool of this invention, a manually operable retraction assist is provided. The tool is provided with a first driving cylinder and a second retracting cylinder in the casing. In normal operation a piston in the driving cylinder drives the driver means to clinch a clip in the anvil, and a retracting piston reciprocably mounted in the retracting cylinder is acted upon by retracting fluid to return the driving piston to an inactive position at which it is ready to initiate a new cycle. If the tool has become jammed, the retracting fluid acting against the retracting piston may be ineffective to return the driving piston to its inactive position. In that event, amanually operable valve means mounted on .the casing may be operated to provide additional retracting fluid to the driving cylinder below the driving piston to provide an assist in retracting the driver means when the retracting piston and cylinder are ineffective to do so. This will clear many jams quickly and without requiring the assembly line on which the tool is being used to be taken out of operation.

These and other advantages and features of this invention will become apparent from the following description and drawings, of which:

DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view, partially in crosssection, of a clip tool of this invention;

FIG. 2 is a fragmentary cross-sectional view taken substantially along the line 22 of FIG. 1;

FIG. 3 is a fragmentary view of the tool of FIG. 1 in an inactive position;

FIG. 4 is a fragmentary view of the too], similar to FIG. 3, in a clinching position;

FIG. 5 is a fragmentary view, similar to FIG. 3 in which the fixedly positioned jaw has been released to provide access below the driver for quickly clearing a am;

FIG. 6 is a cross-sectional view taken substantially along the line 66 of FIG. 1;

FIG. 7 is an enlarged fragmentary view of the anvil jaw members of the tool of FIG. 1 in their closed bottom anvil position;

FIG. 8 is a view similar to FIG. 7 showing the driver blade and jaw members with a clip clinched about a pair of wires;

FIG. 9 is a cross-sectional view taken substantially along the line 99 of FIG. 7;

FIG. 10 is a cross-sectional view similar to FIG. 1 with a portion of the casing rotated to show certain of the air passages not visible in FIG. 1; and

FIG. 11 is a cross-sectional view, partially schematic, showing the valving and fluid supply lines for the tool of FIG. I and is similar to FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT THE CLIP TOOL IN GENERAL An embodiment of the present invention shown in FIG. I is enumerated in its entirety as clip tool 10 and is comprised of a cylinder section 11, a transmission section 40, an anvil section 70 and a magazine assembly 130. The cylinder section 11 is comprised of a driving cylinder 12 and retracting cylinder 22 which mount a driving piston 13 and a retracting piston 23, respectively, and which are operatively connected to move conjointly in the driving and retracting directions. A four-way valve means 90 is provided for selectively directing driving fluid above the driving piston 13 and below the retracted piston 23.

The driving piston 13 is operatively connected to a linkage assembly 41 which transfers the horizontal motion of the pistons into the vertical motion required for a clinching operation. The linkage assembly 41 is pivotally connected to a driver means 42. A magazine assembly 130 is provided to feed clips C into an entry port 71 and advances a clip into the path of the driver means 42 for driving into the anvil jaw section to be clinched, as about a pair of wires (see FIG. 8), by the driver means 42.

N THE CYLINDER SECTION The cylinder section 11 is comprised of a casing lla defining driving cylinder 12 and reacting cylinder 22 in which driving piston 13 and retracting piston 23, respectively, are positioned to reciprocate. In the embodiment of FIG. 1, the retracting piston 23 is formed with driving piston 13, although it is to be understood that the two pistons may be separate and may be provided with operative means for the conjoint movement of each in the driving and retracting directions. The casing surrounding the retracting cylinder portion 22 is dimensioned to serve as a handle for grasping and manual manipulation of the tool.

The driving piston 13 is sealed in the driving cylinder 12 by means of an O-ring 25 and the retracting piston 23 is sealed by O-ring 27 which is mounted in a cylinder collar 28 which is secured to the casing by a retainer 29 and bolts 30. The cylinder collar 28 is sealed in the easing by O-ring 31.

The retracting cylinder 22 comprises an insert sleeve 32 which is sealed to the casing by O-rings 33 and 34 and is held in position adjacent casing shoulder 35 by collar 28 which forms the piston rod sealing segment of the retracting cylinder 23.

Driving and retracting fluid is selectively directed above the driving piston 13 and below the retracting piston 23 by a four-way valve (illustrated in FIGS. 2 and 11) which is actuated by a pilot valve 36. The four-way valve 90 is of a spring loaded, fluid assisted type known in the art. The pilot valve 36 is manually operated by a trigger 37 which is pivotally attached to the casing as by a pin 38 and which is held in the inactive position by the pilot valve 36. Spring 39 biases the pilot valve 36 against the trigger 37 thereby biasing the trigger against stop pin 38a in the inactive position.

When the trigger 37 is pulled to operate tool 10, pilot valve 36 operates to bleed fluid through valve passage 91 and longitudinal passage 92 from actuating port 110 (FIG. 11) to atmosphere, thereby permitting valve spool 106 to move (to the left as seen in FIG. 11) to cause driving fluid to enter the driving cylinder 12 above driving piston 13.

High pressure driving fluid for driving and retracting is supplied to the tool 10 by a supply hose 100 which is attached to a fluid supply tube 86 formed with a tool hanger 150. The lower portion of the tube 86 is provided with a male fitting 93 inserted in casing chamber 94. Fitting 93 defines radial ports 95 and is sealingly retained in the chamber 94 by O-rings 96 and mounting pins 97. The other end of the chamber 94 is fitted with a plug 98 sealingly secured therein by O-rings 99 and pins 100a.

The founway valve 90 comprises a casing bore or chamber 900 in which are disposed valve components including an insert 103, a spool 104, and a sleeve and end plug 105. Insert 103, spool 104 and sleeve and end plug 105 are sealably engaged and fixedly positioned in the chamber 90a, as by O-rings 108 and a set screw 109, and mount a slidable spool 106 and a spring loaded return piston 107 thereon. Spool 106 is sealed against plug 105 by an O-ring 108.

As best illustrated by partially schematic FIG. 11, the tool casing defines ports in communication with valve 90, including an actuating port 110, an exhaust port 111, a retracting fluid port 112 and a driving fluid port 113. In the inactive position of FIG. 2, high pressure fluid is introduced to the valve 90 through ports 95, 114 (in the casing) and 115 (in the sleeve and end plug 105) thereby providing high pressure fluid to the pilot valve 36 through the axial bore in end plug 105 which communicates with an axial passage in spool 106, with spring cavity 117, and with actuatingport 110 and via passages 91 and 92 (FIG. In the inactive position (FIG. 2) spool 106 is biased against shoulder 119 by spring 122 thereby to direct high pressure fluid to retracting port 120 (FIG.- 10) through retracting fluid port 112 and beneath the retracting piston 23. A clearance is provided between the retracting piston 23 and insert sleeve 32 to allow introduction of the retracting fluid at all positions of the piston 23.

When the tool is activated by operating the trigger 37, actuating port 110 and spring cavity 117 are opened to atmosphere and there is a resultant decrease in pressure beneath the piston 107 whereby both the piston 107 and spool 106 move to the left into the position illustrated in FIG. 11 because high pressure fluid acts against the spring force and against piston 107 and spool 106. As the spool 106 moves to the left, driving port 113 is exposed to high pressure fluid which enters passage 121 (FIG. 10) and cylinder 12 above the driving piston 13 to drive the piston 13.

When the spool 106 is in the position of FIG. 11, it seals retracting fluid port 112, sealing it off from the source of high pressure fluid, and placing fluid port 112 in communication with exhaust port 111 to bleed retracting cylinder 22 and to place it in communication with the atmosphere.

When the trigger is released, spring chamber 117 is closed to atmosphere, and high pressure fluid, assisted by the spring 122, returns the valve spool 106 to the inactive position of FIG. 2. i

When the valve spool 106 returns to the inactive position illustrated in FIG. 2, the driving cylinder 12 above the driving piston 13, communicating through passage 121 and port 113 is bled to atmosphere through exhaust port 111, as the retracting cylinder is placed in communication with the retracting fluid port 112 to return the pistons to the inactive position illustrated in FIG. 1.

Driving cylinder 12, beneath driving piston 13 is normally exposed to atmosphere through cylinder port 123 and the communicating air passage in the stem of manually operable valve 124. Valve 124 sealingly engages the casing, as by an O-ring 125, and is maintained in a normally inactive position by fluid pressure in chamber 94 to which the valve 124 is exposed.

If the retracting force provided by the high pressure fluid acting upon retracting piston 23 is insufficient to return driving piston 13 to the inactive position illustrated in FIG. 1, following a cycle of operation, valve 124 may be manually operated to provide a supplemental retracting force. When valve 124 is pushed inwardly, it seals driving cylinder 12 against communication with atmosphere, as by O-ring 126 which is moved into sealing engagement with a bore 127 in which the valve 124 moves. Valve 124 then places the driving cylinder 12'beneath the driving piston 13 in communication with high pressure fluid via chamber 94 to provide an increased retracting force to assist in returning piston 13 to the position of FIG. 1.

So that theclip tool 10 of this invention may be used in a wide variety of environments, fitting 93 and plug 98 may be positioned at either side of chamber 94, i.e.,

may be inserted in chamber 94 from either side. As such, plug 98 defines radial ports 102 communicating with chamber 94 through a central passage 101. When plug 98 is positioned at the opposite side from that illustrated in FIG. 2, high pressure fluid is placed in communication with the axial bore in sleeve and end plug 105 through passage 114 via hose 100, supply tube 86, fitting 93, chamber 94, plug bore 101 and plug ports 102.

THE TRANSMISSION SECTION The forward end of the casing 11a provides transmission section 40 comprising an L-shaped, downwardly facing, open sided transmission chamber 40a. The lower frontal portion of the chamber 40a defines a clearance channel 44 for a reciprocating toggle link 47 and a movable anvil jaw member 74. A ram rod 43 is axially connected to retracting and driving pistons 23 and 13, as by a bolt 46. The ram rod 43 is sealed in the insert sleeve 32 by O-ring 45 and extends beyond the insert sleeve 32 where it is pivotally connected by a roller 51a and pin 52a to linkage assembly 41 which transforms the horizontal movement of the pistons 13 and 23 into the vertical movement required for clinching by the driver and clinching jaws.

The linkage assembly 41 is pivotally connected at its forward end to the driver means 42 by a pin 52b and roller 51b. The driver means 42 is pivotally connected to the toggle link 47 by pin 520. The lower end portion of the driver means 42 defines a generally concave driver surface 42a which strips the leading clip from the remaining clips C and drives it downwardly and clinches it in the anvil jaws 72 and 74. The toggle link 47 is pivotally connected to the upper end of the movable jaw 74 by pin 53 and roller 54. The movable jaw 74 is pivotally attached to the anvil section 70 of the casing by pin 74a.

The forward surface of the lower end portion of the driver means 42 is formed to provide tongues 56 and the confronting surface of the movable jaw 74 has corresponding grooves 57 to receive the tongues, as illustrated in FIG. 8. The number of tongues and grooves corresponds to the number of leg portions in the leg of the clip clinched by the movable jaw 74. The tongues 56 protrude slightly from the driver surface 42a to aid in directing the clip leg around the wires to be joined.

Driver 42 is reciprocal between the positions illustrated in FIGS. 3 and 4. The movement of the driver 42 between these positions is effected by alternately supplying high pressure fluid to and venting high pressure fluid from the pistons 13 and 23 in the manner previously described.

When in the position of FIG. 1, driver 42 is slidably positioned against a guide surface 58 provided in the transmission chamber 40a.

The transmission section 40 of the tool is enclosed at its sides by side plates 59 which are attached to the easing 11a by suitable nuts and bolts 60. A downward facing L-shaped' opening 62 is provided in the side plates 59, as illustrated in FIG. 5, to provide lateral access to the horizontal link 41, driver 42, toggle link 47 and the upper portion of the movable jaw 74.

ANVIL JAW SECTION is reciprocated by link 47 during each stroke of driver 42 into abutment with fixedly positioned or stationary anvil jaw 72 to form a closed bottom anvil. The stationary anvil jaw 72 is pivotally connected to the anvil section of the casing as by a pin 75 and is fixedly positioned by a pull pin 77. The pull pin 77 is attached to a ring clip 78 which is attached to the casing by a cable 79, a tab 80 and cap screw 81 so that it is not lost when the pull pin 77 is retracted.

The anvil jaws 72 and 74 are specially configured to prevent clip jamming which might arise from tolerance and deflection accumulations at the juncture line of conventional anvil jaws and by the entry of a clip leg between the jaws. To that end the upper interior surface portion of each jaw is provided with upwardly facing steps 82 (see FIG. 9), so that as the leg portions of each clip are forced across the juncture line there is no impact with the opposite jaw edge. The size and positions of these steps 82 are determined by the configurations of the clip legs and the number and position of the leg portions. In the embodiment illustrated, one clip leg has two leg portions and the other one leg portion, the leg having two leg portions being positioned initially against jaw 74 to contact the pair of steps 82 as the clip is clinched.

The confronting edges of the jaws 72 and 74 at the juncture line are serrated to interlock in the clinching position, thereby to prevent the entry of a clip leg or leg portion between the jaws at the juncture line.

The L-shaped jaws butt at their juncture line, which, as has been pointed out, is preferably serrated. Unlike .l-shaped jaws, which have a short leg, which returns upwardly, the L-shaped jaws do not return upwardly at their confronting edges. This means that neither of the jaws actually serves as-part of the anvil surface of the other, unlike pairs of J-shaped jaws, which require'the short legs to be brought, respectively, into line with the long legs of the other jaw. As such, there are no short legs which interfere with the closing of the jaws. The short legs of .l-shaped jaws sometimes tend to contact wires to be clinched, thereby hampering closing. Further, for a given desired vertical anvil height, from the driver to the generally horizontal leg of jaw 72, the vertical distance may be less than with J-shaped jaws, where the driver must move to the base of the jaw, but must be spaced the same vertical distance from the upper edge of the short leg of the J. Finally, the distance which the L-shaped jaws must move to close to a butting condition is significantly less than with J- shaped jaws. All of these features simplify the mechanical problems inherent in those tools utilizing J-shaped aws.

THE FEED ASSEMBLY The upper surface of the stationary anvil jaw 72 forms a guid surface 73 for the feed port 71 through which clips C are fed into the driving section. An antibackup link assembly is positioned in this upper surface 73 and comprises a link 83 which is biased in a direction opposite to clip feed by spring 84. The forward end of the link 83 extends in the feed port 71 so that as a clip C is fed from the feed port 71 during each return stroke of the driver 42, the legs of each clip ride over and depress the link 83. The link 83 then returns to the biased position to engage the leading edge of the second clip and thereby prevent rearward motion of the clip.

The magazine assembly is comprised of a clip magazine 13], follower 134, follower handle 135, drum negater 137 and negater 139. The magazine 131 is connected to the case rearwardly of the feed port 71, as by fastener 132 and support bracket 133. The magazine follower 134 is connected to the follower handle 135 by pins 136. The drum negater 137 is attached to the follower handle 135 by a pin 138. As the drum negater 137 retracts the negater 139, the follower 134 is drawn forward to the negater attachment pin 140 until the handle 135 contacts the rear portion of the stationary anvil jaw 72.

The clips C which may be used in this tool are attached in ribbon fashion, leg to leg, across their side surfaces. As the clips C are fed into the feed port 71, the first clip is fed into the drive section so that it may be stripped by the driver surface 42a. The leading leg of the second clip rides over the anti-backup link 83, as illustrated in FIG. 3, so that as the leading clip is stripped by the driver surface 42a, the clips in the magazine are held in place, as illustrated in FIG. 4. The follower 134 is of such a length that it will not feed the last few clips from the feed port 71 of the tool and thus prevents tumbling of the clips, hence prevents jamming for this reason.

OPERATION OF TOOL The clip tool of this invention operates as follows: An in-line, leg connected ribbon of clips C is loaded into the magazine 131 and is fed forwardly by the follower 134. The first clip is fed through the feed port 71 and into position for driving. The leading edge of the secorid clip is forced to ride over the anti-backup link 83, which is then biased to its normal anti-backup position, thus preventing the ribbon of clips in the magazine from being moved rearwardly as the driver surface 42a strips away the leading clip.

The trigger 37 is squeezed, moving the pilot valve 36 inwardly and exposing the actuating port 110 to atmosphere. As high pressure fluid escapes through the pilot valve 36, the valve spool 106 is forced to move in the direction of flow of the fluid placing the retracting cylinder port 112 in communication with exhaust port 111 and causing high pressure fluid to be introduced into driving fluid port 113 above the driving piston. As the driving piston 13 is driven forward, air below the driving piston is vented to atmosphere. As the driving piston l3 and ram rod 43 move forward, horizontal link 41 is forced against the vertical guide surface 58 causing the leading end of the link 41 attached to the driver 42 to move downwardly into the vertical portion of the transmission section 40. As the driver 42 moves downwardly, the leading end of the toggle link 47 and the upper portion of the movable anvil jaw 74 are moved forwardly into the clearance 44 causing the anvil jaw 74 to rotate about pin 74a toward the stationary jaw 72 to form a closed bottom anvil as the driver surface 42a is stripping the leading clip and driving it downwardly into the anvil section 70. As the clip is driven downwardly in anvil section, the leg portions of the clip strike their respective jaws and move across the juncture line of the anvil jaws. As the leg sections are clinched, they are directed inwardly by the leading edge of their respective protruding tongues 56 in the driver 42 and thereby prevented from jamming between the driver 42 and the movable anvil jaw 74.

When the trigger 37 is released, the pilot valve 36 is closed by spring 39. As the pressure in passages 91, 92 and 110 equalizes with that of the high pressure fluid in the supply hose 100, the valve spool 106 is forced to return to its inactive position by the valve spring 122 exposing retracting fluid port 112 to high pressure fluid, to drive the retracting piston 23. At the same time, the driving fluid port 113 and passage 121 are Additional clearing is provided by the stationary anvil jaw 72 which may be swung down after removing the pull pin 77 to provide full and open access to the clinching area so that a jammed clip'may be easily and quickly removed without substantial downtime for the tool.

While this invention is susceptible of embodiment in many different forms, there has been shown and ,describedin detail a preferred embodiment of the invention, with the understanding that'the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the embodiment illustrated. The scope of the invention will be pointed out in the appended claims.

I claim: 1

l. A pneumatically operated clip tool comprising: a casing defining a first driving cylinder and a second retracting cylinder; a driving piston reciprocably mounted in said driving cylinder; aretracting piston reciprocably mounted in said retracting cylinder; means for providing driving fluid to said driving cylinder above said driving piston and for normally providing retracting fluid to said retracting cylinder below said retracting piston; a clip driver means operatively connected to said driving piston for driving a clip, means operatively connecting said driving and retracting pistons for conjoint movement in a first driving direction and in a second retracting direction; a clinching anvil disposed beneath said driver means, said clinching anvil comprising a fixedly positioned clinching jaw member mounted on said casing, and release means for readily releasing said clinching jaw member from its fixed position, thereby to provide free and full access from below said driver means; and manually operable valve means mounted on said casing for selectively introducing retracting fluid to said driving cylinder below said driving piston to assist in retracting said driver means and said retracting piston when said retracting fluid, piston and cylinder are ineffective to retract said driver means.

2. A clip tool in accordance with claim 1 wherein said clinching anvil comprises two generally L-shaped clinching jaw members, one being said fixedly positioned jaw member and the other being a member movable toward said fixedly positioned member to butt against said fixedly positioned member to form a closed bottom anvil section and away from said fixedly positioned member to provide a space between said members, said movable jaw member being attached to a linkage means whichcooperates with said clip driver, whereby when said driving piston is moved in said first direction, said movable member and said driver move together to drive and clinch a clip.

'3. A clip tool'in accordance with claim 2 wherein the confronting butting edges of said L-shaped jaw members are correspondingly serrated and mesh to form said closed bottom anvil section.

4. A clip tool in accordance with claim 2 wherein said driver defines a tongue confronting said movable jaw member and the confronting surface of said movable jaw member defines a groove receiving said tongue,

thereby to prevent the entry of portions of a clip to be driven between said confronting surfaces as said driver drives a clip toward said fixedly positioned clinching jaw member, said tongue protruding from said driver thereby to direct said portions of a clip inwardly to facilitate clinching.

5. A clip tool in accordance with claim 2 wherein said L-shaped jaw members each defines an upwardly facing step positioned adjacent the juncture of said members when they are in their-closed bottom anvil position to guide clip edges across the juncture of said jaw members without striking the edges of said members as a said clip is driven and clinched.

6. A clip tool in accordance with claim 2 in which said driving piston moves in a direction which is generally normal to the direction in which said clip driver is mounted to reciprocate.

7. A clip tool in accordance with claim 2 further including: a magazine, said magazine being secured to said casing and being positioned with a clip discharge end adjacent a feed opening in said casing, said magazine being adapted to feed a ribbon of U-shaped clips attached leg to leg into said feed opening to a clip driver blade, means for preventing clips fed into said feed opening from moving backwardly through said feed opening to said discharge end, said means comprising an anti-backup assembly, said anti-backup assembly. comprising a link and means for resiliently biasing said link into a first upper clip leg engaging position, said link extending upwardly into the path of clips positioned in said magazine and being adapted to be resiliently biased to a second retracted position as a clip is moved from said discharge end through said feed opening and to resiliently return to said first upper position to act against a leg of a clip to prevent its backward movement.

8. A clip tool in accordance with claim 7 wherein said magazine includes a follower for feeding clips toward said feed opening, said follower and magazine being so proportioned that said follower cannot feed all of the clips in the magazine through said feed opening thereby to leave several clips in said magazine, the clips thereby serving to prevent tumbling of other clips fed into said feed opening to be driven by said clip driver blade.

9. A pneumatically operated fastener tool comprising: a casing defining a driving cylinder and a driving piston reciprocably mounted in said cylinder for movement along a given horizontal axis and driven by a fluid means, a fastener driver means movable with said piston, a rigid fluid tube connected to said casing at a point substantially in line with the centroid of said tool and including hanger means for suspending said fas- 4 dance with claim 9 wherein said tool is pivotally conncted to said fluid tube, whereby said tool may be rotated in said vertical plane.

11. A pneumatically operated fastener tool in accor dance with claim 10 wherein said tool defines a bore traversing the tool for receiving a leg of said fluid tube from either side, said leg being retractably retained in said bore and being rotatable therewithin, thereby to pivot said tool with respect to said'fluid tube, said driving fluid passage being defined by said leg. 

1. A pneumatically operated clip tool comprising: a casing defining a first driving cylinder and a second retracting cylinder; a driving piston reciprocably mounted in said driving cylinder; a retracting piston reciprocably mounted in said retracting cylinder; means for providing driving fluid to said driving cylinder above said driving piston and for normally providing retracting fluid to said retracting cylinder below said retracting piston; a clip driver means operatively connected to said driving piston for driving a clip, means operatively connecting said driving and retracting pistons for conjoint movement in a first driving direction and in a second retracting direction; a clinching anvil disposed beneath said driver means, said clinching anvil comprising a fixedly positioned clinching jaw member mounted on said casing, and release means for readily releasing said clinching jaw member from its fixed position, thereby to provide free and full access from below said driver means; and manually operable valve means mounted on said casing for selectively introducing retracting fluid to said driving cylinder below said driving piston to assist in retracting said driver means and said retracting piston when said retracting fluid, piston and cylinder are ineffective to retract said driver means.
 2. A clip tool in accordance with claim 1 wherein said clinching anvil comprises two generally L-shaped clinching jaw members, one being said fixedly positioned jaw member and the other being a member movable toward said fixedly positioned member to butt against said fixedly positioned member to form a closed bottom anvil section and away from said fixedly positioned member to provide a space between said members, said movable jaw member being attached to a linkage means which cooperates with said clip driver, whereby when said driving piston is moved in said first direction, said movable member and said driver move together to drive and clinch a clip.
 3. A clip tool in accordance with claim 2 wherein the confronting butting edges of said L-shaped jaw members are correspondingly serrated and mesh to form said closed bottom anvil section.
 4. A clip tool in accordance with claim 2 wherein said driver defines a tongue confronting said movable jaw member and the confronting surface of said movable jaw member defines a groove receiving said tongue, thereby to prevent the entry of portions of a clip to be driven between said confronting surfaces as said driver drives a clip toward said fixedly positioned clinching jaw member, said tongue protruding from said driver thereby to direct said portions of a clip inwardly to facilitate clinching.
 5. A clip tool in accordance with claim 2 wherein said L-shaped jaw members each defines an upwardly facing step positioned adjacent the juncture of said members when they are in their closed bottom anvil position to guide clip edges across the juncture of said jaw members without striking the edges of said members as a said clip is driven and clinched.
 6. A clip tool in accordance with claim 2 in which said driving piston moves in a direction which is generally normal to the direction in which said clip driver is mounted to reciprocate.
 7. A clip tool in accordance with claim 2 further including: a magazine, said magazine being secured to said casing and being positioned with a clip discharge end adjacent a feed opening in said casing, said magazine being adapted to feed a ribbon of U-shaped clips attached leg to leg into said feed opening to a clip driver blade, means for preventing clips fed into said feed opening from moving backwardly through said feed opening to said discharge end, said means comprising an anti-backup assembly, said anti-backup assembly comprising a link and means for resiliently biasing said link into a first upper clip leg engaging position, said link extending upwardly into the path of clips positioned in said magazine and being adapted to be resiliently biased to a second retracted position as a clip is moved from said discharge end through said feed opening and to resiliently return to said first upper position to act against a leg of a clip to prevent its backward movement.
 8. A clip tool in accordance with claim 7 wherein said magazine includes a follower for feeding clips toward said feed opening, said follower and magazine being so proportioned that said follower cannot feed all of the clips in the magazine through said feed opening thereby to leave several clips in said magazine, the clips thereby serving to prevent tumbling of other clips fed into said feed opening to be driven by said clip driver blade.
 9. A pneumatically operated fastener tool comprising: a casing defining a driving cylinder and a driving piston reciprocably mounted in said cylinder for movement along a given horizontal axis and driven by a fluid means, a fastener driver means movable with said piston, a rigid fluid tube connected to said casing at a point substantially in line with the centroid of said tool and including hanger means for suspending said fastener tool in a horizontal orientation, said fluid tube adapted to be placed in communication with said cylinder when said tool is actuated, and comprising the sole passage of driving fluid to said tool.
 10. A pneumatically operated fasteNer tool in accordance with claim 9 wherein said tool is pivotally connected to said fluid tube, whereby said tool may be rotated in said vertical plane.
 11. A pneumatically operated fastener tool in accordance with claim 10 wherein said tool defines a bore traversing the tool for receiving a leg of said fluid tube from either side, said leg being retractably retained in said bore and being rotatable therewithin, thereby to pivot said tool with respect to said fluid tube, said driving fluid passage being defined by said leg. 